1. A Science Odyssey: People And Discoveries: Niels Bohr Short biographical article.Category Science Physics History People Bohr, Niels......Niels Bohr 1885 1962 Niels Bohr was born and educated in Copenhagen,Denmark. He lived, worked, and died there, too. But his mark http://www.pbs.org/wgbh/aso/databank/entries/bpbohr.html

Niels Bohr Niels Bohr was born and educated in Copenhagen, Denmark. He lived, worked, and died there, too. But his mark on science and history was worldwide. His professional work and personal convictions were part of the larger stories of the century. At the University of Copenhagen, he studied physics and played soccer (though not as well as his brother, who helped the 1908 Danish soccer team win an Olympic silver medal). After receiving his doctorate in 1911, Bohr traveled to England on a study grant and worked under J.J. Thomson, who had discovered the electron 15 years earlier. Bohr began to work on the problem of the atom's structure. Ernest Rutherford had recently suggested the atom had a miniature, dense nucleus surrounded by a cloud of nearly weightless electrons. There were a few problems with the model, however. For example, according to classical physics, the electrons orbiting the nucleus should lose energy until they spiral down into the center, collapsing the atom. Bohr proposed adding to the model the new idea of quanta put forth by Max Planck in 1901. That way, electrons existed at set levels of energy, that is, at fixed distances from the nucleus. If the atom absorbed energy, the electron jumped to a level further from the nucleus; if it radiated energy, it fell to a level closer to the nucleus. His model was a huge leap forward in making theory fit the experimental evidence that other physicists had found over the years. A few inaccuracies remained to be ironed out by others over the next few years, but his essential idea was proved correct. He received the Nobel Prize for this work in 1922, and it's what he's most famous for. But he was only 37 at the time, and he didn't stop there. Among other things, he put forth the theory of the nucleus as a liquid drop, and the idea of "complementarity" that things may have a dual nature (as the electron is both particle and wave) but we can only experience one aspect at a time.

3. Bohr Niels Henrik David From FOLDOC bohr niels Henrik David. history of science, philosophy of science danishphysicist (18851962). Although best known for his contributionshttp://www.swif.uniba.it/lei/foldop/foldoc.cgi?Bohr Niels Henrik David

Niels Bohr Niels Henrik David Bohr, a Danish physicist and Nobel laureate, made basic contributions to nuclear physics and the understanding of atomic structure. Bohr's theory of atomic structure, for which he received the Nobel Prize in physics in 1922, was published in papers between 1913 and 1915. His work drew on Rutherford's nuclear model of the atom, in which the atom is seen as a compact nucleus surrounded by a swarm of much lighter electrons. Bohr's atomic model made use of quantum theory and the Planck constant (the ratio between quantum size and radiation frequency). The model suggested that an atom emits electromagnetic radiation only when an electron in the atom jumps from one quantum level to another. This model contributed enormously to future developments of theoretical atomic physics. In 1916 Bohr went to the University of Copenhagen as a professor of physics, and in 1920 he was made director of the university's newly formed Institute for Theoretical Physics. There Bohr developed a theory relating quantum numbers to large systems that follow classical laws, and made other major contributions to theoretical physics. His work helped lead to the concept that electrons exist in shells and that the electrons in the outermost shell determine an atom's chemical properties. He also served as a visiting professor at many universities. In 1939, recognizing the significance of the fission experiments of the German scientists Otto Hahn and Fritz Strassmann, Bohr convinced physicists at a scientific conference in the U.S. of the importance of those experiments. He later demonstrated that uranium-235 is the particular isotope of uranium that undergoes nuclear fission. Bohr then returned to Denmark, where he was forced to remain after the German occupation of the country in 1940. Eventually, however, he was able to escape to Sweden, under peril of his life and that of his family. From Sweden the Bohrs traveled to England and eventually to the United States, where Bohr joined in the effort to develop the first atomic bomb, working at Los Alamos, New Mexico, until the first bomb's detonation in 1945. He opposed complete secrecy of the project, however, and feared the consequences of this ominous new development. He desired international control.

Niels Bohr

Niels Bohr - born Oct. 7, 1885, Copenhagen, Den. d. Nov. 18, 1962, Copenhagen in full NIELS HENRIK DAVID BOHR Danish physicist who was the first to apply the quantum theory, which restricts the energy of a system to certain discrete values, to the problem of atomic and molecular structure. For this work he received the Nobel Prize for Physics in 1922. He developed the so-called Bohr theory of the atom and liquid model of the atomic nucleus. Early life Bohr's father, Christian Bohr, professor of physiology at the University of Copenhagen, was known for his work on the physical and chemical aspects of respiration. His mother, Ellen Adler Bohr, came from a wealthy Jewish family prominent in Danish banking and parliamentary circles. Bohr's scientific interests and abilities were evident early, and they were encouraged and fostered in a warm, intellectual family atmosphere. Niels's younger brother, Harald, became a brilliant mathematician. Bohr distinguished himself at the University of Copenhagen, winning a gold medal from the Royal Danish Academy of Sciences and Letters for his theoretical analysis of and precise experiments on the vibrations of water jets as a way of determining surface tension. In 1911 he received his doctorate for a thesis on the electron theory of metals that stressed the inadequacies of classical physics for treating the behaviour of matter at the atomic level. He then went to England, intending to continue this work with Sir J.J. Thomson at Cambridge.

8. BOHR Niels - ENGLISH Last updated 05.08.2001 063402. Niels Bohr was born in Copenhagenin Denmark in 1885. His father was a professor of physiologyhttp://www.volny.cz/michal_bachman/bohren.htm

Last updated: 05.08.2001 06:34:02

Niels Bohr was born in Copenhagen in Denmark in 1885. His father was a professor of physiology at the University of Copengagen. Niels attended the same university and was a distinguished soccer player as well as a brilliant student. Bohr studied at J. J. Thomson ´s Cavendish Laboratory and at Rutherford ´s laboratory. At the young age of 28, while working with Rutherford, he invented the first effective model and theory of the structure of the atom. His work ranks as one of the truly great examples of an imaginative mind at work. He was awarded the 1922 Nobel Prize for physics for his study of the structure of atoms. During Worls War 2, Bohr and his family escaped from occupied Denmark to the United States. He and his son, Aage, acted as advisers at the Los Alomos Atomic Laboratories, where the atom bomb was developed. Thereafter, Bohr concerned himself with developing peaceful uses of nuclear energy. Aage Bohr, Neil´s son was awarded the Nobel Prize for physics in 1975. Optimální rozliení - 1024x768, minimálnì 800x600.

16. Niels Bohr Niels Bohr The Old Quantum Theory. Niels Bohr (1885 1962) was a youngpost-doctoral fellow from Denmark working with Ernest Rutherfordhttp://www.chembio.uoguelph.ca/educmat/chm386/rudiment/tourquan/bohr.htm

Niels Bohr The Old Quantum Theory

Niels Bohr (1885 - 1962) was a young post-doctoral fellow from Denmark working with Ernest Rutherford in England during these heady days of discovery. The experimental feature plaguing their minds was the structure of the atom. How could the electrons orbit the nucleus and not lose energy? Why was this configuration stable? Look here for a brief presentation of the derivation of his theory. The atom that Bohr envisioned had these stable orbits because of quantization of the angular momentum. The resulting image, such as at right, is the one with which the world is most familiar when discussing atomic structure, namely, small electron balls whizzing around a central nucleus. But why was it quantized? And his theory provided no means for calculating the intensities of these atomic lines - only their positions. And of course there was no concept of chemical bonding or any further explanations beyond the hydrogen atom. And yet, his success was indisputable. Where was the connection? Author: Dan Thomas email: Last Updated: Friday, July 5, 1996

Resources Menu Categorical IndexLibraryGalleryNiels Bohr Physicist The opposite of a correct statement is a false statement. But the opposite of a profound truth may well be another profound truth. Niels Bohr Niels Bohr was born on October 7, 1885 in Copenhagen, Denmark. Bohr made numerous contributions to our understanding of atomic structure and quantum mechanics. He won the 1922 Nobel Prize for physics, chiefly for his work on the structure of atoms. Bohr received his doctorate in physics from the University of Copenhagen in 1911. He then traveled to Manchester, England to study under British physicist Ernest Rutherford. In 1913 Bohr published a theory about the structure of the atom based on an earlier theory of Rutherford's. Rutherford had shown that the atom consisted of a positively charged nucleus, with negatively charged electrons in orbit around it. Bohr expanded upon this theory by proposing that electrons travel only in certain successively larger orbits. He suggested that the outer orbits could hold more electrons than the inner ones, and that these outer orbits determine the atom's chemical properties. Bohr also described the way atoms emit radiation by suggesting that when an electron jumps from an outer orbit to an inner one, that it emits light. Later other physicists expanded his theory into quantum mechanics. This theory explains the structure and actions of complex atoms. Bohr became a professor of physics at the University of Copenhagen in 1916. In 1920 Bohr was named director of the newly constructed "Institute of Theoretical Physics" at the University. Bohr became a Fellow of the Royal Society of London in 1926, receiving the Royal Society Copley Medal in 1938. During World War II, Bohr fled Copenhagen to escape the Nazis. He traveled to Los Alamos, New Mexico to advise the scientists developing the first atomic bomb. He returned to Copenhagen after the war and later promoted the peaceful use of atomic energy.

18. Niels Bohr Archive A repository of primary material for the history of modern physics, pertaining in particular to the early development of quantum mechanics and the life and career of niels bohr. News, collections, library, publications and seminars.http://www.nba.nbi.dk/

Practical Information People Annual Reports: Recent News Collections: Niels Bohr Other People ... Links Niels Bohr Archive Release of documents relating to 1941 Bohr-Heisenberg meeting DOCUMENTS RELEASED 6 FEBRUARY 2002 The family of Niels Bohr has decided to release all documents deposited at the Niels Bohr Archive, either written or dictated by Niels Bohr, pertaining specifically to the meeting between Bohr and Heisenberg in September 1941. There are in all eleven documents. The decision has been made in order to avoid possible misunderstandings regarding the contents of the documents. The documents supplement and confirm previously published statements of Bohr's recollections of the meeting, especially those of his son, Aage Bohr. The documents have now been organised, transcribed and translated into English at the Niels Bohr Archive. Because of the overwhelming interest in the material, it has been decided that the material should be published in full instead of being made available to scholars upon individual application, as is normal practice at the Niels Bohr Archive. This has been done by placing facsimiles, transcriptions and translations on this website

20. Niels Bohr - Biography niels Henrik David bohr was born in Copenhagen on October 7, 1885, as the son of Christian bohr, Professor of Physiologyhttp://www.nobel.se/physics/laureates/1922/bohr-bio.html

Niels Henrik David Bohr was born in Copenhagen on October 7, 1885, as the son of Christian Bohr, Professor of Physiology at Copenhagen University , and his wife Ellen, Adler. Niels, together with his younger brother Harald (the future Professor in Mathematics), grew up in an atmosphere most favourable to the development of his genius - his father was an eminent physiologist and was largely responsible for awakening his interest in physics while still at school, his mother came from a family distinguished in the field of education. After matriculation at the Gammelholm Grammar School in 1903, he entered Copenhagen University where he came under the guidance of Professor C. Christiansen, a profoundly original and highly endowed physicist, and took his Master's degree in Physics in 1909 and his Doctor's degree in 1911. While still a student, the announcement by the Academy of Sciences in Copenhagen of a prize to be awarded for the solution of a certain scientific problem, caused him to take up an experimental and theoretical investigation of the surface tension by means of oscillating fluid jets. This work, which he carried out in his father's laboratory and for which he received the prize offered (a gold medal), was published in the Transactions of the Royal Society, 1908.